1. Field of the Invention
The field of present invention relates to fitness application and more particularly to a system and a method for facilitating personal physical fitness diagnostic evaluation based on heart rate variability analysis during orthostatic intervention.
2. Description of the Prior Art
The ability of the human organism to withstand physical strain is one of the most important characteristics of health. We can easily distinguish a person who is able to run 10 miles from an individual that cannot even walk 100 yards without a break. The difference between them is in their physical fitness. What is “physical fitness”? According to physiology, it is the ability of the cardio vascular system to provide the function of the organism in the state of heightened strain. Therefore, in assessing the state of the cardio vascular system we are also assessing the state of physical fitness. In recent times, for this purpose, the method of analyzing heart rate variability during the orthostatic challenge test became widely used.
It is well known that orthostatic challenge test is one of the most informative methods used to detect subtle changes in cardiovascular function and specifically its regulatory mechanisms. When body's position is changed from supine to standing, specific changes in heart rate and blood pressure happen as a compensatory reaction of the body. This standup maneuver does not cause any significant physical exertion to a healthy individual. However, if body's regulatory mechanisms do not have adequate functional capacity or there is subtle cardiovascular deficiency then this maneuver can show regulation mechanism dysfunction.
With the help of heart rate variability analysis, it is possible to assess these regulatory mechanism dysfunction. Multiple research studies have shown that reaction of the cardiovascular system on changing body posture and speed of its compensation depends on fitness level. The most indicative parameter of this Heart Rate Variability test is a pattern of heart rate changes caused by a standup maneuver. The weaker and slower this reaction is the less an organism is fit and susceptible to physical exertions, which means lower level of fitness.
Modern techniques of HRV (Heart Rate Variability) analysis allow us to determine an almost exact cardiovascular function condition during the orthostatic challenge test. For example, the Heart Rhythm Scanner program, developed by Biocom Technologies, includes Cardiovascular Health Test. It makes an assessment of the cardiovascular function condition based on two variables:                Cardiovascular Tolerance—indicates dynamic regulatory reserve of the cardiovascular system responsible for a quick reaction to rapid changes in the body's condition.        Cardiovascular Adaptation—indicates the ability of the cardiovascular system to adapt to physiological changes in the body and establish a new stable regulatory state.        
The higher the variables of these results the better the ability of the organism to withstand physical strain and as a result a higher level of fitness.
Heart Rate Variability (HRV) is a powerful, very accurate, reliable, reproducible, yet simple method of fitness assessment. Regardless of the vast amount of research in this field, its use by fitness specialists has not yet spread to reach full potential. However, the use of this method will give an individual the ability to customize his physical strain according to cardiovascular function. This will help to avoid overstrain of the organism during workout.
It has been previously proposed to construct fitness monitors to count the number of strides when individual is running. From this, the fitness monitor calculates the distance run by multiplying the number of steps times the individual's stride length. The number of calories consumed by the individual is automatically estimated using the elapsed exercise time and individual is average speed.
Recently, the capacity of the individual's cardiovascular system to bring oxygen to the body tissues has been determined to be the most meaningful index of fitness level. This fitness index is usually expressed in terms of the volume of oxygen taken up by the cardiovascular system, per kilogram of body weight, per minute, this fitness index is commonly referred to as the maximum oxygen intake, or VO2max. Generally, this fitness index is higher, the greater the level of fitness is for a given individual. The application of maximal oxygen uptake VO2max as an index of fitness is discussed, e.g., in Astrand and others, for example, in the Journal of Physiology, November 1963. Portable heart rate monitors based on measurement of this index came into existence back in 1982 when Polar launched the first wireless wearable heart rate monitor.
All the fitness evaluation inventions that are based on approximate assessment VO2max have multiple drawbacks. First, all these methods are based on only one fitness parameter (maximal oxygen uptake level) and they require the individual to go through a strict training protocol in order to provide the assessment. Second, these methods require special skills for performing assessment and therefore, usually performed with assistance of the exercise physiologist. In addition, such methods take substantial time to complete, not very precise, difficult to quantify, require to input multiple parameters. Thus, despite the existing methods for fitness evaluation based on Heart Rate Variability Analysis, there is a need for a quick, quantifiable and comprehensive method of fitness assessment, which can be easy performed without supervision and other complications.
* Based on our previous study's result, invented method of Fitness Score assessment well correlated with VO2max approach.